Orthodontics is the branch of dentistry concerned with correcting and preventing irregularities of the teeth and poor occlusion. During orthodontic treatments, teeth are fitted with braces and moved into proper alignment, etc., by forcibly controlling movement of the teeth with the brace hardware and various appliances. Frequently, during the orthodontic treatment, it is necessary to distalize a primary tooth, e.g., an upper molar relative to a secondary tooth, e.g., a premolar or bicuspid. Such distalization of the primary tooth creates space between the two teeth, and more importantly moves the primary tooth into a desired posterior position.
Distalizing appliances for moving the primary tooth relative to a second tooth are known in the art. For example, head gear is perhaps the best known such orthodontic appliances for distalizing a primary tooth relative to the secondary tooth. With head gear, the orthodontic bracket fitted to the upper molar brace is provided with a head gear tube. The head gear wire is inserted into the head gear tube and tensile forces are exerted on the head gear wire by a strap extending behind the patient's neck. Head gear are extremely effective in distalizing the upper molars, however are plagued with certain disadvantages. For example, the head gear apparatus is traditionally uncomfortable, causing discomfort to the patient's neck and sometimes mouth. Further, head gear can be unsightly due to the external components. Also, and most importantly, the use of head gear requires patient cooperation. Thus, if the patient declines to wear the head gear appliance because of comfort, or concern for appearance, the upper molars will not be distalized.
Other orthodontic appliances have been proposed as an alternative to such head gear. For example, U.S. Pat. No. 4,595,361 to Blechman et al, issued Jun. 17, 1986, discloses an orthodontic appliance including repelling magnets disposed between the primary and secondary teeth for distalizing the primary tooth. In each of the several embodiments disclosed in Blechman et al, one magnet is supported in a head gear tube in the bracket of the primary tooth brace. For this reason, additional orthodontic appliances cannot be used on the primary tooth at the same time as the Blechman et al appliance. Accordingly, the Blechman et al appliance cannot be used simultaneously with head gear to further accelerate distalization of the primary tooth.
Another example of a molar distalizing appliance may be had in U.S. Pat. No. 5,064,370 to Jones, issued Nov. 12, 1991. The Jones patent discloses a compression spring distalizing appliance in lieu of the Blechman et al magnets. The bracket on the primary tooth brace includes a head gear tube and a standard archwire receptacle fixedly supported thereon. The compression spring of the distalizing appliance is carried on a main support shaft which engages the primary tooth brace through both the head gear tube and the archwire receptacle. In other words, all available tubes and/or receptacles in the bracket of the primary tooth brace are employed during treatment with the Jones appliance. Therefore, additional appliances, such as head gear, cannot be used simultaneously with the Jones distalizing appliance.